There is a storage system that has a failover function by including redundantly configured storage apparatuses. Some storage apparatus is mounted with different kinds of drives mixedly to perform automated storage tiering by controlling storage locations of data so as to optimize access performance and data storage cost. A storage management apparatus manages execution of the automated storage tiering by instructing the storage apparatus to perform detection of an access frequency of data and data relocation corresponding to the access frequency. As a related art document, there is Japanese Laid-open Patent Publication No. 2013-210930.